import React, { useReducer} from 'react';

function ReducerDemo(){
    const [ count , dispatch ] =useReducer((state,action)=>{
        switch(action){
            case 'add':
                return state+1
            case 'sub':
                return state-1
            default:
                return state
        }
    },0)
    return (
        <div>
            <h2>现在的分数是{count}</h2>
            <button onClick={()=>dispatch('add')}>Increment</button>
            <button onClick={()=>dispatch('sub')}>Decrement</button>
        </div>
     )
}

function countReducer(state,action){
    switch(action.type) {
        case 'add':
            return state + 1;
        case 'sub':
            return state - 1;
        default: 
            return state;
    }
}
export default ReducerDemo